Propeller-gear housing



Oct. 31, 1933.

F. T. IRGENs PROPELLER GEAR HOUSING Filed Jan. 22, 1932 2 Sheets-Sheet 2- Patented Oct. 31, 1933 UNITED STATESI PATENT GFFICE Outboard Motors Corporation, Wis., a corporation of Michigan Milwaukee,

Application January 22, 1932. Serial No. 585,084

25 Claims.

This invention relates to improvements in propeller gear housings. It is the primary purpose of the present invention to provide a so-called lower end unit for a boat propulsion motor which will oier a minimum resist-ance to travel through the water whileproviding improved facilities for circulating water to the engine cylinders for cooling purposes.

More specically stated it is my purpose to provide a gear housing assembly in which improved disposition of shaft bearings reduces the thicka ness of the housing below the water line; to.provide a device in which the horizontal cross section below the water line differs from that above the water line in a manner ideally adapted to minimize resis'ance to travel while providing an improved water inlet; to provide a novel and improved disposition of under water exhaust whereby the discharge of exhaust gases and waste coolant, is facilitated by the movement of the device through the water; to provide an assembly in which the propeller is a tractor propeller so located that its slip stream will facilitate water circulation through the cooling system of the motor without the use of speed-obstructing parts,

the propeller location being also adapted to aciliv tate exhaust movement of the products o cornbustion and waste cooling without the interier' ence caused by propeller in the ordinary location; and to provide an improved gear housing so designed that the propeller driven therethrough will be disposed immediately beneaih the rear of a boat hull'to which the propeller mechanism is attached.

In the drawings:

Figure 1 is a side view partially in axial section and partially in elevation, oi a' device embodying this invention.

Figure 2 is a section through the drive shaft housing and exhaust manifold in the plane indicated at 2-2 in Fig. l, the propeller gear housing being shown ,in plan.

Figure 3 is a detail View taken in section in the plane indicated at 3-3 in Fig. l.

Figure 4 is a detail view taken in lsection in thep' ane indicated at 4 4.- in Fig. 1.

Figure 5 is a detail View taken in section in the plane indicated at 5 5l in Fig. 2. 50

the line indicated at 6 6 in Fig. 2.

Figure '7 is a detail view taken in section in the plane indicated at'7-7 in Fig. 1. g Like parts are identified by the same reference characters throughout the several Views.

Figurel tl is a detail view taken in section on,

(Cl. 11S- 17) The bracket 10 is adapted to support tiltably upon bearing stud 11 an outboard motor power y head of any conventional design, to which the vertical dri-ve shaft 12, tubular drive shaft housing 13, muiier 14, and water supply pipe' 15, will e0 be understood to -be connected in the usual way. The bracket is provided at 16 with a thrust block of semi-annular form adjustable between arms 17 to provide an open seat for the thrust bearing 18 which encircles the drive shaft housing, being c5 clamped thereon at 19 and bolted to the gear housing 20 hereinafter to be described.

The unique design oi" the gear casing as here= inafter explained from the standpoint of the accompanying drawings, will be best understood in m the light of the foregoing statement of objects. The upper end portion 21 of the gear casing is relatively very wide as clearly shown in Figs. 2, 5 and 6, The bearingsleeve 18 terminates in a flange or shoe 22 secured by bolts 23 to the gear 75 housing. An annular channel 24 in the under surface of this shoe communicates through port 25 with the forward compartment 26 oi the gear housing and serves as a passage for "conveying cooling water from compartment 26 to the supply g@ pipei leading to the cooling jackets or the power head cylir'iders.` p

The exhaust pipe 30 is of comparatively large cross section and is received within an annular flange 3i affording communication 'with the rear g5 compartment 32 of the gear housing. The iront compartment 26 is separated from rear eoinpartment 32 by an annular partition 33 through which extends a stub drive shaft 34 having a bearing` Within sleeve 35 which is ntted within the ann e@ nular partition 33. This shaft extends into the gear case compartment 36 of the .gear housing with which the interior oi the tubular partition f 33 is in communication.

The stub shaft 34 is keyed at 37 to the coupling 95 member 38 at thelower end of drive shaft i2. A flange 39 on the shoe 22 seats within the 'exsanded-upper end e0 of the tubular partition 33 against the outer race of a ball bearing e2 of which the inner race is made fast on the stub shaft 34. This bearing not only serves the function of a radial bearing, but also absorbs all vertical thrusts in the drive shaft 12 and stub shaft 34, thereby making it unnecessary to provide any anti-friction bearing below the water line von the loo.

vstub shaft.

In a recess barely 'large enough to receive it, I provide a driving pinion 43 keyed to the stub shaft and held in place thereon by a nut 44. Thelower end 45 of shaft 34 is of reduced di- 110 supported by bracket 47 from the partition wall. This feature relieves the bearing 35 of the heavy bearing pressures to which it would otherwise be subjected. This is another means of avoiding the use oi' anti-friction bearings below the water line along the drive shaft.

A driven gear 50 meshes with pinion 43 and has `a. hub portion provided with a ball bearing 51 capable of handling both radial and axial thrusts. The propeller shaft 52 is received within the hub of gear 50 and keyed thereto. In addition to the bearing thus provided at -its rearward end, the propeller shaft has a further bearing in a sleeve 53 which is carried by the forward closure 54 for the gear case compartment 36.

In order to anchor closure 54 without obstructing the tube-like portion of the gear housing through which the ball bearing assembly 51 is introduced, I have undercut an annular groove at 55 into which the anchoring segments 56 are receivable after the ball bearing assembly 51 is in place. Cap screws 57 hold the closure cap 54 to the respective anchoring segments while at the same time maintaining the anchoring segments expanded into their respective portions of the groove 55.

The tractor propeller 58 has a hub portion 59 which is complementary to the exterior-periphery oi' the closure cap 54 and to the adjacent portions of the gear housing in providing a suitable stream line contour. The blades of the propeller are so disposed on the hub as to eliminate the relatively inemcient high pitched shank with which most propeller blades are provided.

Immediately adjacent the upward portion of the circular path described by the propeller blades in their rotation with the device at rest, I have provided openings 60 leading into the compartment 26 of the gear housing. These openings are conveniently made by U-shaped core members having relatively long and short legs, the long leg being anchored at its extremity in the annular partition 33. The openings produced in the partition by this mode of anchoring the cores are closed by the bearing sleeve 35 as shown in Fig. 1.

If the contour of the lower portion of the device were completed along the stream line form to which attention has been previously called, the lower unit would have an4 outline substantially as indicated inbroken lines in Fig. 1. For purposes hereinafter to be described, however, the housing is terminated at margin 61 which has an arcuate extent along a chord inclined to the horizontal whereby some of the rear portion and some of the bottom portion of the projected design of stream line is omitted. This leaves at 6l a relatively large opening communicating with compartment 32 of the gear housing. Through this opening a plug 62 is incidentally accessible for lubrication of the gear casing compartment 36.

It will be noted from comparison of the various figures found in the drawings that a number of different cross sections are employed at different horizontal levels in this device. Reference has already been made to the very wide section employed at the upper end portion 21 of the gear housing. Immediately beneath the upper end the walls of the gear housing converge rather sharply,

In the planev .ameter and is conined in a bearing sleeve 46 mains substantially the same width, but its for- ,ward margin is blunt as shown in Fig. 4. Still lower down, in' the plane of the propeller shaft, the greater width necessitated by the anti-friction bearing -assembly 51 and the gearing requires an elongation of the stream line contour.

lThis contour is workedput symmetrically about the axis of the propeller shaft, the horizontal contour being substantially the same as that illustrated in vertical section in Fig. l. This contour, however, is broken by the provision of the discharge port at 61 as above described.

I shall now point -out' the advantages of the various special features of form as enumerated hereinbefore.

Due to the proximity of the assembly to the stern of the boat to which bracket l0 is attached, the water level will be approximately in the plane represented by the bottom of the boat. This level will rise slightly at the rear of the boat but in general will not exceed in height the plane indicated at 3-3 in Fig. 1.

It being one of the major purposes of this invention to minimize resistance of `the water to movement of the gear housing therethrough, the intermediate portion of the housing has been made as thin as possible. As shown in Figs. 3 and 4, its maximum thickness is approximately that of its tubular partition 33 required to provide the bearing for the drive shaft. It has been found that the best stream line contour for use `at or immediately above the surface of the water Where `Waves are encountered, is the sharp pointed contour shown in Fig. 3. Accordingly` those portions of the device at and near the water level are sharply pointed at their forward margins while maintained at the minimum width aforesaid.

The expansion of the gear housing at its upper end performs numerous functions. In the iirst place, it provides an`adequate anchorage or connectionwith the drive shaft housing 13. In Athe second place, it provides the necessary width for the thrust bearing 42, thus making it possible to dispose this bearing wholly above the water level to avoid increasing the width of the gear housing below the water. In the third place, the large cross section at the top of the gear housing provides an opening of adequate size to receive the lower'end of the tube 30 through which exhaust gases from the engine and waste coolant water are discharged. It will be noted that as the width of chamber 32 is decreased below the exhaust pipe 30, ,its lengthy is increased so that chamber 32 has substantially the same cross section area as the lower end of exhaust pipe 30.

It has been found that in undisturbed or relatively undisturbed water, the blunt stream line contour shown in Fig. 4 affords less resistance than a stream line more sharply pointed. Consequently, the contour of my improved housing, instead of remaining constant, is blunted below the water level. Incidentally, this fact facilitates the provision of apertures 60 through which cooling water is admitted to chamber 26 for delivery through pipe 15 to the engine jacket.

It will be noted that contrary to the usual practice, a tractor propeller is employed. Such propellers are not new in themselves but the 1,932,523 but also by the propeller slip stream. In addition, an extremely emcient aspiration of entrained exhaust gases occurs due to the disposition of thedischarge port 61 at the point usually occupied by the propeller.

As above indicated, the stream line surfaces of the gear housing are convergent toward relatively remote trailing margins at the point where they are interrupted by the provision of the open.- ing at 6l. These contours are Worked out to produce very little disturbance in the movement of the device through the water, the contours represented by the broken lines being also the paths on which the water itself tends to move in closing behind the, gear housing. The interruption oi these contours along the margin of di tends to produce a vacuum at said port between the bodies or water at either side of the path or movement oi the housing. if this vacuum were uurelieved eddy currents would bc established the water traversed by the apparatus and considerable loss ci power would result. The present design :is however, that the vacuum is constantly relieved by ealiaust gases and cooling water passing downwardly to pipe 3o and chamber 32 and leaving the gear housing through the port at di. Such gases and cooling water are entrained by the mass of water through which the apparatus is moving, so that back pressure is wholly eliminated and an actual depression is established throughout the chamber 32, exhaust pipe 3d, and rnuiler lll, thereby greatly contributing to the volumetric efficiency of the engine entiployed as a power head with the device.

it will be seen that the construction, shape, and disposition. of parts is carefully worked out to provide harmoniously for the reduction of water resistance to the movement of a geai` housing or lower unit embodying this invention. While l have shown the device associated with an out" board motor bracket at lil, it will be understand that it is serviceable in connection with any type ci prime mover requiring the advantages achieved in the structure recited.

i claim:

l. As a new article oi manufacture, a propeller gear housing of stream line cross section divided vertically int-o forward and rearward compartments by a tubular partition, a gear case in the lower portion oi housing with which the interior oi said partition communicates, a forwardly projecting 'part providing iairing for said gear case, said housing being abruptly terminated in an aperture directlylat the rear of said gear case whereby to provide an opening substantially equal in capacity to, and adording communication with, said rear compartment.

2. As a new article of manufacture, a propeller gear housing generally of stream line cross section and having a lower gear casing portion. said housing being provided in itsstern apex with a cavity adapted for the discharge of waste fluids, the stream lined walls of said housing being abruptly terminated at the lower stern portions thereof, providing a port directly rearwardly of `said casing portion, communicating with -said cavity, substantially equal to said cavity in cross section and adapted in the movement of said housing through a body of liquid to aspirato said fluids from said cavity.

3. The combination with a propeller gear housing. of an upright drive shaft extending therein, a propeller gear. shaft operatively driven theren from and projecting forwardly from said housing, a tractor propeller mounted on said shaft,

and an exhaust pipe leading to said housing, said housing providing iny its stern an exhaustr passage opening downwardly and rearwardly immediately behind said propeller shaft and adja# cent the bott-om of said housing.

4. In a device of the character described, the combination with a propeller gear housing of substantially stream line cross section in all horizontal planes below the water level, said housing having a sharp bow apex adjacent the water level and a blunt bow apex substantially throughout those portions therebeneath, of a drive shaft extending into said housing, a propeller shaft geared to said drive shaft and projecting forwardly therefrom, and means dividing said housing into bow and stern compartments, said housn ing having a water admission port in its blunt apex portion and a fluid discharge port in its lower stern portion substantially immediately behind said propeller shaft, said ports communh eating with the respective compartments.

5. The combination with a propeller gear housing of stream lined horizontal cross section through-out the major portion oi its vertical height, of partition means dividing the interior of said housing into a bow supply' passage, a stern discharge passage and a gear casing below said supply passage, a propeller shaft extending through the gear casing, a propeller having a hub on said shaft, and a drive shaft tube disposed between said passages and communicating with the walls of said gear casing, said housing being abruptly terminated. immediately behind and substantially at the level of said gear casing on a line having a vertical component whereby said discharge passage opens downwardly and lill@ rearwardly directly behind said gear casing sub- 'stantially at the level of said hub.

d. The combination with a propeller gear housing oistream lined horizontal cross section throughout the major portion of its vertical height, of partition means dividing the interior o said housing into a bow supply passage, a stern discharge passage, a gear casing below said supply passage, and a drive shaft tube disposed oetween said passages and communicating with the walls of said gear casing, said housing being abruptly terminated behind said gear casing on a line having a vertical component whereby said discharge passage opens downwardly and rearwardly, a drive shaft extending through said tube, a propeller shaft extending forwardly from said drive shaft and geared thereto within said casing, and a tractor propeller on said propeller shaft adjacent the bow portion of said housing and directly ahead of said discharge passage, said bow portion being ported adjacent the path oi propeller movement, whereby to afford access of the propeller slip stream to the supply passage within said housing.

'i'. combination with a partially submersible gear housing having sides of stream lined horizontal outline enclosing an interior cavity and upwardly divergent above the water line, partition means providing a drive shaft tube intermediate the bow and stern portions of said interior cavity, and an anti-friction bearing concentric with said tube and disposed between the upwardly flaring' housing being substantially equal to that` of said lod support and the upper and lower ends of said housing being of increased thickness, a radial and axial anti-friction bearing mounted in the upper end of said housing about said drive shaft section, a. driving .pinion on said section adjacent the `lower end of the housing, a bearing for said shaft section below said pinion, a propeller shaft journaled in the lower end of the housing and provided with a gear meshing with said pinion, and a support for said housing adapted to maintain its water line below its top portion of increased thickness.

` 9. The combination with a propeller gear housing having sides of stream lined contour, of a drive shaft section provided with a bearing support integral with said housing, the maximum thickness of the intermediate portion of the housing being substantially equal to that of said support and the upper and lower ends of said housing being of increased thickness, a radial and axial anti-friction bearing mounted in the upper end of said housing about said drive shaft section, a driving pinion on said section adjacent the lower end of the housing, a bearing for said shaft section below said pinion, a propeller shaft journaled in the lower end of the housing and provided with a gear meshing with said pinion, and a support for said housing adapted to maintain its Water line below its top portion of increased thickness, said housing having an interior cavity in its stern provided with a connection to receive a pipe for waste fluid and opening downwardly and rearwardly for the discharge of such fluids.

l0. In a device of the character described, the combination with a propeller gear case, of an upward extension thereof comprising a gear housing of less width than the case, the walls of said housing being of stream line contour below the Water level and being divergent to provide a top portion of increased width, a tubular guide comprising a partition between the walls of said housing opening downwardly into said case, a drive shaft section provided with an anti-friction bearing in the enlarged top portion of said housing above the water line thereof, and a sleeve bearing within said case, a drive shaft tube connected with said first mentioned housing, a drive shaft within said tube connected with said drive shaft section and supported in part by said anti-friction bearing, and a propeller shaft provided with a driven gear meshing with said pinion within said case.

11. The combination with a shaft housing and an exhaust pipe wholly at the rear thereof, of a propeller gear housing of generally stream lined contour connected to said shaft housing and of less width below the water line than said pipe, said gear housing being widened above its normal water line and provided with aconnection to said pipe, the stern portion of said gear housing comprising a discharge passage opening downwardly and rearwardly.

12. The combination with an exhaust pipe, of a propeller gear housing of generally stream lined contour widened above its normal water line and provided with a connection to said pipe, the stern portion of said housing comprising a discharge passage opening downwardly and rearwardly, said passage being of decreased transverse dimensions below said pipe and elongated longitudinally to a degree sufficient to maintain a substantially uniform cross sectional area approximately equal to the cross sectional area of said pipe at its connection therewith.

13. The combination with a drive shaft housing.

of a terminal shoe therefor, a propeller gear housing having an enlarged upper end connected with said shoe, a tubular partition extending through said housing substantially in alignment with said drive shaft tube, a drive shaft extension within said housing provided with an anti-friction radial and thrust bearing in the enlarged upper end thereof, a drive shaft within said tube connected with said extension, and a propeller shaft geared to said extension Within said housing.

14. The combination with a drive shaft housing, of a terminal shoe therefor, a propeller gear housing having an enlarged upper end connected with said shoe, a tubular partition extending through said housing substantially in alignment with said drive shaft tube, a drive shaft extension within said housing provided with an antifriction radial and thrust bearing in the enlarged upper end thereof, a drive shaft within said tube connected with said extension, and a propeller shaft geared to said extension within said housing, together with an exhaust pipe communicating with the interior of said housing be hind said tube, said housing having an exhaust fluid passage bounded forwardly by said tubular partition and opening downwardly adjacent the bottom of the housing.

15. The combination with a drive shaft tube, of a propeller gear housing providing internally an extension of said tube and having an exhaust fluid passage at the rear of said extension, an exhaust pipe connected with said passage, drive shaft means extending through said tube and ex tension, and a tractor propeller operatively connected with said drive shaft means to receive motion therefrom, said passage being open at the bottom of said housing directly below said pipe and behind said propeller and said housing being 'abruptly terminated about said opening, whereby water traversed by said housing will tend to aspirate exhaust fluid from said passage.

16. The combination with a drive shaft tube, pf a propeller gear housing providing internally an extension of said tube and having an exhaust fluid passage at the rear of said extension, an exhaust pipe connected with said passage, drive shaft means extending through said tube and cxtension, and a tractor propeller operatively connected with said drive shaft means to receive motion therefrom, said passage being open at the bottom of said housing and said housing being abruptly terminated about said opening, whereby water traversed by said housing will tend to aspirate exhaust fluid from said passage said housing being provided with a passage forwardly of said tubular'extension and having an apex port immediately adjacent said propeller, together with a pipe communicating with said last mentioned passage and disposed between the 4drive shaft tube and the exhaust pipe.

17. The combination with a partially submer sible gear housing having a relatively thin intermediate portion and a relatively wider lower portion, of a driven gear in said lower portion, an anti-friction bearing directly' supporting said gear from said housing, a propeller shaft connected with said gear and provided with a propeller exteriorly of said housing, an upright drive shaft extending through said relatively thin intermediate portion, a driving pinion meshing with said gear and disposed upon said drive shaft, a bearing for said drive shaft beneath the water level in said housing, and a thrust bearing for said drive shaft below said pinion and adjacent said 18. The combination with a gear housing having walls of stream line contour with a sharp apex adjacent the water line of said housing and a relatively blunt, apex below the water line of said housing, of a gear case formed integrally in the .lower portion of said housing and of greater thickness than the portion of said housing immediately thereabove, a drive shaft guide compris- \ing a partition in said housing defining a passage, said blunt apex being provided with a port communicating with said passage, a water supply -pipe communicating with said passage, a drive shaft within said guide, a propeller shaft operatively geared within said case to said drive shaft and projecting forwardly therefrom, means providing a streamline forward extension of said ycase about said propeller shaft, and a tractor propeller connected with said shaft and associat- Aed with said means immediately adjacent said port.

19. The combination with a gear housing having walls of stream line contour with a sharp apex adjacent the water line of said housing and a relatively blunt, ported, apex below the water lineof said housing, of a gear case formed integrally in the lower portion of said housing immediately thereabove, a drive shaft guide comprising a partition in said housing defining a passage with which said port communicates, a water supply pipe communicating with said passage, a drive shaft within said guide, a propeller shaft operatively geared within said case to said drive shaft and projecting forwardly therefrom, means providing a stream line forward extension of said case about said propeller shaft, and a tractor propeller connected with said shaft and associated with said means immediately adjacent said port, said means comprising a closure for said case and a detachable anchoring device expanded within said case and secured to said closure.

20.l In a device of the character described, the combination with a propeller gear case and an anti-friction bearing journaled therein, said case having an undercut groove adjacent said bearing, of an anchoring device expanded into said groove, and a closure for said case connected with said anchoring device`and adapted to maintain the expanded condition thereof while anchored thereby.

21. The combination with a propeller gear case yand an anti-friction bearing mounted therein, said case being provided with an lundercut groove, of segment means receivable into said groove,

and a cap for said case provided with a propeller shaft bearing and bolted to said segment means at distant parts of said case, the connection of said cap with said segment means being adapted to maintain said segment means expanded in said groove while anchoring said cap to said case.

22. As a new article of manufacture, a gear housing of stream line contour having an upright tubular partition defining a bow passage, a downwardly and rearwardly opening stern passage and( a drive shaft passage, an additional partition deflning a gear case below said bow passage communicating with said drive shaft passage, said gear casing opening forwardly, a closure for the forward end of said gear casing provided with a bearing, and a plug affording access to said gear casing from said stern passage.

23. As a new article of manufacture, a gear housing of stream line contour having a relatively sharp apex at substantially the level of its water line merging with'a relatively blunt apex therebeneath, partition means within said housing defining a drive shaft passage, a gear case communicating therewith and disposed therebeneath, a bow passage provided with a port opening through the blunt apex of said housing, and

a stern passage freely communicating with the exterior of said housing; the stream line contours of said housing being abruptly interrupted to afford such communication, a removable closure for the forward end of said gear case, and a drive shaft bearing support projecting from said partition means within said gear case in alignment with said drive shaft passage.

24. As a new article of manufacture, a gear housing having an interior gear chamber entirely closed at the rear, said housing being formed with an interior cavity extending downwardly behind said chamber, and sides of stream line contour abruptly terminating at the rear lower portion of said housing and thereiproviding a port communicating with said cavity and disposed to lie between masses of water parted by said housing in its passage therethrough.

25. The combination with a tractor propeller having a hub, of a stream line gear housing having contours complementary to those of the hub of said propeller and provided internally with a cavity opening externally immediately behind said propeller and intersected by the line of the axis of the propeller whereby the slip stream of said propeller will tend to aspirato fluid from said cavity.

FINN 'I'. IRGENS. 

